Dam cleanup underway in Britannia watershed

Britannia Mine dams built in early 1900s being decommissioned

Photo submittedCarving a notch A heavy equipment operator works on one of the dams in the Britannia watershed.

A years-in-the-making project is underway in the backcountry around Squamish.

Several dams in the Britannia watershed — built in the 1910s to supply power to the Britannia Mine — are being decommissioned.

"The dams were all deteriorating. Then it became a question of what to do with them, whether they could be fixed or just left in place and inspected," explained Bruce O'Neill, project director of provincial dam interests for the Ministry of Forests' resource stewardship division.

Since the dams weren't being used for anything, O'Neill said it made the most sense to decommission them.

"It just became a point where there was a small public safety risk, and it was expensive just doing what we were doing with them," he said.

"Britannia Creek has had a series of debris flows in its past. Most recently there was a big debris flow there in 1991, so if one of these dams was to fail it could potentially trigger another debris flow. That would be the biggest safety issue."

An added benefit to removing the dams is that they'll no longer be blocking fish passage, O'Neill said.

"The main purpose of taking these dams down was to reduce the public safety risk. The fisheries is really a side benefit," he said.

"There wouldn't be enough fisheries benefit to justify taking these dams down... but there is some fisheries benefit in terms of reconnecting chunks of the river that have been separated."

Of the eight dams, four will be decommissioned this year, two will be dealt with next year and two are small enough that they won't require any work, O'Neill said.

The work involves carving four-metre-by-nine-metre notches into the dams.

The cost of the project for this year is about $750,000.

Squamish Mayor Patricia Heintzman, who also sits on the board of the Squamish-Lillooet Regional District (SLRD), said the project has been a long time coming.

"Certainly the SLRD has been working on all the tunnel dam issues for as long as I've been on the board," Heintzman said.

"In the last couple of years we've started to see some movement, so it's really great that (the province is) taking the initiative and going to clean up the dams up there, because it should have been done years ago."

To see the work being done is satisfying not just for Heintzman, but for all the other SLRD board directors and government officials that have worked on the project over the years, she said.

"I know government has to go through their prioritization, and there was quite a bit of analysis and research that needed to be done on the dams to figure out the scope of the problem and the cost of the problem," Heintzman said.

"So I think there's a lot of satisfaction that it's finally being done, and ultimately it will create a safer and a better environment for the river too, and a safer environment for anyone downstream."

The Britannia Mine — at its peak the largest copper producer in the entire British Commonwealth — was originally closed in 1974. Acid runoff from the mine created pollution problems in Howe Sound for decades.

The province began fixing the site's pollution and contamination problem in 1997 with the introduction of its Contaminated Sites Regulation.